The colon, ileum and knee synovium from 50 animals sacrificed from the FDA colony will serve as the basis to determine if there exists a cause-effect relationship between inflammatory bowel disease (IBD) and arthritis. Ten normal animals will serve as the control group. The evaluation will consist of quantitation using morphometrics and immunostaining for 1) tumor necrosis factor (TNFa); 2) IgA producing cells; 3) IgG producing cells; and 4) the production of nitrous oxide (NO synthetase). Colon and knee joints will be cultured. Mucosal immunity will be evaluated with the IgA and IgG immunostains and mediators of the IBD consists of TNFa and NO immunostaining. Correlation of these parameters with isolation of pathogens in the joint and colon will be made. During 1995, samples were collected from 20 animals and evaluation is underway.